Hand-held pipettor

1. A hand-held pipettor comprising: a piston received in one end of a cylinder; a pipettor tip removably secured to an opposite end of said cylinder; a manually driven plunger for reciprocating said piston through a selected stroke along a longitudinal axis to aspirate fluid into and to expel the thus aspirated fluid from said pipettor tip; mutually spaced stop members engagable with said manually driven plunger to define together a range of the stroke; a mechanism including a stepper motor and a rotatable member defining one of said stop members, said mechanism being responsive to control signals for adjusting a range of said stroke by adjusting a position of said rotatable member along said longitudinal axis; a central processing unit; and a voice recognition system that decodes verbal commands and outputs the result to said central processing unit, which in turn generates said control signals.

2. The hand-held pipettor of claim 1 further comprising an encoder assembly operatively coupled with said stepper motor and operative to generate feedback signals to said central processing unit indicative of the range of said stroke.

3. The hand-held pipettor of claim 1 wherein said stepper motor includes an output shaft that is mechanically coupled to said rotatable member, and said motor is operative to vary the distance between said mutually spaced stop members.

4. The hand-held pipettor of claim 3 further comprising an encoder assembly operatively coupled with said stepper motor and operative to generate feedback signals to said central processing unit indicative of the position of the said one stop member.

5. The hand-held pipettor of claim 1 further comprising a sleeve surrounding and axially shiftable on said cylinder, said sleeve being urged in one direction into a retracted position by the pipettor tip removably secured to the said opposite end of said cylinder, and being shiftable in the opposite direction to dislodge said pipettor tip from said cylinder.

6. The hand-held pipettor of claim 5 further comprising spring means for resiliently shifting said sleeve in the opposite direction.

7. The hand-held pipettor of claim 6 further comprising lock means for accommodating movement of said sleeve in the said one direction, and for preventing movement of said sleeve in the said opposite direction, and manually operable means for releasing said lock means to accommodate the resilient shifting of said sleeve in the said opposite direction.

8. The hand-held pipettor of claim 6 further comprising pneumatic means for retarding the rate of movement of said sleeve in the opposite direction.

9. A hand-held pipettor comprising: a piston received in one end of a cylinder; a pipettor tip removably secured to an opposite end of said cylinder; a manually driven plunger that is depressible to reciprocate said piston through a selected stroke along a longitudinal axis to thereby aspirate fluid into and to expel the thus aspirated fluid from said pipettor tip; mutually spaced stop members engagable with said manually driven plunger to define together a range of the stroke; a drive collar operatively coupled to one of said stop members; a processing system; a voice recognition system that receives and decodes verbal commands and outputs the results to said processing system which generates motor control signals; and a motor that receives the motor control signals and includes a motor output shaft coupled to said driver collar, said motor being responsive to the motor control signals to vary the range of the stroke defined by the mutually spaced stop members and the plunger by adjusting a position of said rotatable member along said longitudinal axis to thereby vary the volume of fluid being aspirated into and expelled from said pipettor tip.

10. The hand-held pipettor of claim 9 further comprising an encoder assembly operatively coupled with said motor and operative to generate feedback signals to said processing system indicative of the range of said stroke.

11. The hand-held pipettor of claim 9 wherein said output shaft is mechanically coupled to one of said stop members, and said motor is operative to vary the distance between said mutually spaced stop members.

12. The hand-held pipettor of claim 11 further comprising an encoder assembly operatively coupled with said drive motor and operative to generate feedback signals to said processing system indicative of the position of the said one stop member.

13. The hand-held pipettor of claim 9 further comprising a sleeve surrounding and axially shiftable on said cylinder, said sleeve being urged in one direction into a retracted position by the pipettor tip removably secured to the said opposite end of said cylinder, and being shiftable in the opposite direction to dislodge said pipettor tip from said cylinder.

14. The hand-held pipettor of claim 13 further comprising spring means for resiliently shifting said sleeve in the opposite direction.

15. The hand-held pipettor of claim 14 further comprising lock means for accommodating movement of said sleeve in the said one direction, and for preventing movement of said sleeve in the said opposite direction, and manually operable means for releasing said lock means to accommodate the resilient shifting of said sleeve in the said opposite direction.

16. A hand-held pipettor comprising: a piston received in one end of a cylinder; a pipettor tip removably secured to an opposite end of said cylinder; a manually driven plunger that is depressible to reciprocate said piston through a selected stroke along a longitudinal axis to thereby aspirate fluid into and to expel the thus aspirated fluid from said pipettor tip; mutually spaced stop members engagable with said manually driven plunger to define together a range of the stroke; a processing system; a threaded screw member defining one of said stop members; a voice recognition system that receives and decodes verbal commands and outputs the results to said processing system which generates motor control signals; and a motor that receives the motor control signals and includes a motor output shaft coupled to said threaded screw member, said motor being responsive to the motor control signals to vary the range of the stroke defined by the mutually spaced members and the plunger by adjusting a position of said rotatable threaded screw member along said longitudinal axis to thereby vary the volume of fluid being aspirated into and expelled from said pipettor tip.

17. The hand-held pipettor of claim 16 further comprising an encoder assembly operatively coupled with said motor and operative to generate feedback signals to said processing system indicative of the range of said stroke.

18. The hand-held pipettor of claim 16 wherein said output shaft is mechanically coupled to one of said stop members, and said motor is operative to vary the distance between said mutually spaced stop members.

19. The hand-held pipettor of claim 18 further comprising an encoder assembly operatively coupled with said motor and operative to generate feedback signals to said processing system indicative of the position of the said one stop member.

20. The hand-held pipettor of claim 16 further comprising a sleeve surrounding and axially shiftable on said cylinder, said sleeve being urged in one direction into a retracted position by the pipettor tip removably secured to the said opposite end of said cylinder, and being shiftable in the opposite direction to dislodge said pipettor tip from said cylinder.